JPH01271917A - Permanent magnet type alternating high magnetic field generator - Google Patents

Abstract

PURPOSE:To control the frequency of an alternating magnetic field generated in a clearance between rolls by the control of the number of the rotations of the rolls by arranging oppositely in parallel a pair of roll cores on whose circumference plural magnetic poles to stretch in the direction of their axes are arranged and rotating them synchronously in opposite directions. CONSTITUTION:Plural (an even number of) permanent magnet magnetic poles are arranged around the major diameters of the yokes of a roll cores 2a and 2b. When using the title device, the roll cores 2a and 2b are rotated synchronously in the opposite directions through a silencing flat gears 4a and 4b by a driver 7. Next, a sheet or tape-like object 8 to be processed is inserted into the clearance between outer casing roll shells 6a and 6b in the direction of an arrow X, it is passed and a disorientation processing and a demagnetization processing are performed. At this time, by controlling the number of rotations, the alternating magnetic field frequency generated in the clearance can be freely changed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a permanent magnet type alternating high magnetic field generator for performing non-orientation processing or demagnetization/demagnetization of magnetic disks, magnetic sheets, magnetic tapes, etc. It is something.

[Prior art] Material base sheets for magnetic disks, etc., are coated with magnetic particles that serve as magnetic memory on the surface of the base material, and then the natural orientation (orientation in the natural direction based on the shape of the magnetic particles) is eliminated. As a method, it is necessary to perform non-orientation treatment (randomizing treatment) immediately before solidifying the coating solvent, and in the manufacturing process of various magnetic tapes, magnetic sheets, etc., after magnetic orientation, drying and solidification, noise cancellation Therefore, it is necessary to completely demagnetize it. In addition, in recent years, magnetic particles with high coercive force (coercive force) have been used to enhance magnetic memory functions.

At present, non-orientation processing or demagnetization is often performed using AC electromagnets or AC solenoid coils powered by commercial AC power supplies, and when attempting to perform non-orientation or demagnetization processing on materials with high coercive force, it is extremely expensive. Although it is necessary to provide a magnetic field and a high-frequency alternating magnetic field, it is extremely difficult to obtain a high magnetic field and a high-frequency alternating magnetic field due to the characteristics of AC coils, and even if it were possible, it would be necessary to use a considerable amount of equipment and consume a large amount of power.

[Problems to be solved by the invention] The aim of the present invention is to solve the problem of the current AC electromagnet or solenoid.
Instead of a coil, a permanent magnet device is used to reduce weight, size, and power consumption.Furthermore, the strength and frequency of the alternating magnetic field can be easily selected to match the properties and form of the memory magnetic particles used, and the magnetic particles are non-oriented. The aim is to further enhance the effect (randomizing effect) or demagnetizing effect.

[Means for Solving the Problems] Therefore, according to the present invention, first and second roll cores facing in parallel, each having a plurality of magnetic poles extending in the axial direction arranged on the circumference; a gap between the first and second roll cores adapted to allow the material to pass therethrough; and magnetic poles of the first and second roll cores facing each other at opposing positions across the gap. An alternating high magnetic field generating device is provided, comprising: driving means for synchronously rotating the first and second roll iron cores in opposite directions.

[Operation] Two rolls in which a plurality of magnetic poles (multipole) composed of rare earth magnets, etc. are arranged in the axial direction are opposed in parallel across a gap, and the opposing magnetic poles are the same or different. , the drive means (drive device 7 and spur gears 4a and 4
b)), which rotates synchronously in opposite directions to each other. This allows the rolls to be rotated synchronously in opposite directions by the roll gap, either in an orientation that connects the two roll axes (different polarity vs. inner type), or in a tangential orientation to the roll outer circumference (same polarity opposite A high alternating magnetic field is generated in the magnetic field.

The synchronous rotational drive of the two rolls allows the rotation speed to be freely selected using a drive means, such as a continuously variable speed device such as an inverter. Through this control, it is possible to freely control the frequency of the alternating magnetic field generated in the gap between the rolls.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a front sectional view showing an alternating high magnetic field generator according to an embodiment of the present invention, in which two rolled iron cores 2a and 2b consisting of yokes have one side located inside the gear housing, respectively. Two bearing devices 3a+, 3a, and 3b
+ and 3bx, the rolls are rotatably supported so as to maintain mutual parallelism, and each of the bearing devices 3m+ and 3bx
between az and 3b.

Silencing spur gears 4a and 4b are fixed to the portions of the roll cores 2a and 2b between and 3bt, respectively.
The respective muffling spur gears 4a and 4b are connected to roll cores 2a and 2.
b are meshed to enable synchronous rotation. And on either one of the roll cores 2& and 2b,
That is, in the illustrated case, a drive device 7 having a rotation speed control function is connected to the roll core 2b at its left end, and under the action of the drive device 7 and spur gears 4a and 4b, the roll core 2a and 2b are synchronously rotated in opposite directions.

Although FIG. 1 shows the case where the roll cores 2a and 2b are supported on one side, the roll cores 2a and 2b are supported on both sides so as to maintain the parallelism of the layers. You can also do it like this.

A plurality (an even number) of permanent magnet magnetic poles 5a and 5b made of rare earth magnets or the like are arranged around the outer diameter of the yoke of the rolled iron cores 2a and 2b. And roll iron core 2a
and a plurality of permanent magnet magnetic poles 5a, as well as an outer cylindrical roll shell 6a and a non-magnetic and non-metallic material fixed to the gear housing 1, respectively. 6b, and a minimum gap is provided between the outer cylinder roll shells 6a and 6b, which is sufficient to allow the object to be processed, that is, the object to be processed 8, to easily pass therethrough. By providing the fixed outer cylinder roll shells 6a and 6b in this manner, the safety of the object to be processed 8 passing through the gap is guaranteed.

Each roll core 2a and 2b has a circular bar shape on one side, that is, the left side of the figure, so as to be rotatably supported by a bearing device, and on the other side, that is, the right side, as shown in FIGS. 2A and 2B. Figures 2A and 2B are hollow regular polygons (even angles) as shown in Figure 2B.
The figure shows a side sectional view of the roll core seen from line ■-■ in Figure 1, and Figure 2A shows each roll core 2a and 2b.
The other side, that is, the right side, has a cross-sectional shape having a circular hollow part and a square outer shape, and both roll cores 2a and 2b are arranged in a 4-pole homopolar facing type. Moreover, FIG. 2B shows each roll core 2a and 2
The right side of b has a cross-sectional shape having a circular hollow part and a regular hexagonal outer shape, and both rolled iron cores 2a and 2b
The case is shown in which the 6 poles are arranged in opposite poles. For any P4 key, the sides of the regular polygon, that is, the outer diameter, are
A plurality of (even number) permanent magnet magnetic poles 5a and 5b made of rare earth magnets etc. are arranged alternately with opposite polarity,
The permanent magnet magnetic poles 5a and 5b facing each other in the gap between the roll cores 2a and 2b are arranged so that the same poles face each other and rotate synchronously in the same-polar facing type shown in FIG. 2A, and in the different type shown in FIG. 2B. In the pole-opposed type, different poles are arranged so as to face each other and rotate synchronously.

In use, first, the roll core 2b is rotationally driven by a drive device 7 such as a variable speed drive motor, and the roll core 2b is rotated via spur gears 4b and 4a.
a, thereby causing the roll cores 2a and 2b to
Next, the sheet-shaped or tape-shaped workpiece 8, which is rotated in opposite directions as shown by arrows Ya and Yb in FIGS. 2A and 2B, is rotated by an outer cylinder roll - It is inserted and passed through the gap between the shells 6a and 6b, and non-orientation processing, demagnetization processing, etc. are performed.

In this case, the polarities of the opposing magnetic poles 5a and 5b are
By selecting the homopolar facing type shown in FIG. 2A or the different polarity facing type shown in FIG. The direction of movement can be either horizontal, which is the direction of movement, or vertical, at 90 degrees to the surface of the object to be processed.

Taking the case of the opposite polarity opposing type shown in FIG. 2B as an example, when a sheet-shaped or tape-shaped workpiece 8 is passed through the gap between the roll cores at a speed, the alternating magnetic field change curve shown in FIG. As shown in , due to its structure, the change in magnetic field above the center line of the gap between the synchronously rotating roll cores, that is, the line through which the workpiece passes, has a peak at the opposite pole position of the center L2 between the roll cores, and the workpiece In the direction of movement, the magnetic field is overturned in a quadratic curve, resulting in a so-called attenuated alternating magnetic field, which conforms to the theory of demagnetization and demagnetization.

Here, the tip shape of the plurality of magnetic poles 5a and 5b arranged on the roll core is such that the outer diameter of the roll core forms an arc concentric with the circle of the roll shell as shown in FIGS. 2A and 2B. Instead, it can be a parabola or a small circle with a smaller radius of curvature as shown in Figure 4, and the curvature can be changed in this way, or the diameter width of the magnetic pole, the anode and By changing the interval etc., it is possible to obtain an alternating magnetic field curve extremely close to a sinusoidal waveform.

In addition, as shown in the roll rotation speed - frequency conversion table in Figure 5, the number of magnetic poles of the opposing roll cores (parameters in the figure)
By controlling the rotation speed (horizontal axis), the alternating magnetic field frequency (vertical axis) can be freely changed, making it easy to set the appropriate frequency according to the required reversal stress of the magnetic particles coated on the workpiece. can be selected.

Furthermore, by appropriately selecting the relationship between the feeding speed of the workpiece and the alternating frequency, high-speed feeding is possible in a high frequency range, and productivity can be improved.

[Effects of the Invention] As described above, according to the present invention, the excitation mechanism that forms the magnetic field uses high-performance permanent magnets such as rare earth magnets to form a static magnetic field, and the rotating mechanism further generates an alternating high magnetic field. This method has the advantage that not only a coil device and electric power for excitation are not required, but also management is extremely simple, and the device itself is extremely small and lightweight. In this regard, when generating an alternating magnetic field using an electromagnet or solenoid coil powered by a conventional AC power supply, it is extremely difficult to obtain a high magnetic field due to its self-induced resistance, and even if it were possible, it would require considerable power consumption. From this point of view, the effects of the present invention are tremendous.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing a permanent magnet type alternating high magnetic field generator according to an embodiment of the present invention, and FIGS. 2A and 2B are
Fig. 1 is a side sectional view taken from an-m in Fig. 3. Fig. 3 is a diagram showing the change curve of the alternating magnetic field in the gap between the rolls, taking a different pole facing type as an example. Fig. 4 shows the tip shape of the magnetic poles being smaller. 2A and a side sectional view similar to FIG. 2A when the radius of curvature is present, and FIG. 5 is a graph showing the relationship between roll rotation speed and alternating magnetic field frequency.・Housing, 2a and 2b are roll cores, 3a+, 3i, 3b
1 and 3bt are bearing devices, 4a and 4b are muffling spur gears,
51 and 5b are permanent magnet poles, 6a and 6b are rolls.
The shell, 7 is a driving device, and 8 is an object to be processed. ¥2A Figure 2B Figure 3 Figure 1

Claims (1)

[Scope of Claims] First and second rolled iron cores facing in parallel, each having a plurality of axially extending magnetic poles arranged circumferentially, and adapted to allow a workpiece to pass therethrough; A gap between the first and second roll cores, and magnetic poles of the first and second roll cores are made to face each other at positions facing each other with the gap between the first and second roll cores.
An alternating high magnetic field generator comprising: drive means for synchronously rotating roll iron cores in opposite directions;